button-cell

Noun

(plural button cells)

A small coin cell

button cell - Computer Definition

A single-cell battery that is used to power wristwatches, computer clocks, hearing aids and other small devices. Also called a "coin cell," button cells look like small, squat silver cans from five to 25mm in diameter. Delivering from one to two volts, button cells come in alkaline, silver, zinc-air and lithium varieties.